Each sentence below demonstrates a specific type of error involving
internal punctuation, usually involving a comma.

Discussion and revision following each example explain and illustrate
correct punctuation:

1. Misplaced punctuation

This approach requires an effective model risk governance program, and
crucially, validation of the model by an independent party.

A comma is needed after program only if what follows is an
independent clause. In this case, the rest of the sentence is merely the
rest of an extended compound predicate. However, crucially is a
parenthetical, and a comma is required before as well as after it: “This
approach requires an effective model risk governance program and,
crucially, validation of the model by an independent party.”

2. Missing punctuation

Specifically her portfolio did not include the required number of
samples.

An adverbial introduction must be set off from the main clause by a comma:
“Specifically, her portfolio did not include the required number of
samples.”

3. Unpaired punctuation

The survey found increasing demand for customer experiences that are
difficult, if not impossible to deliver with legacy systems.

Related to the misplaced and missing examples above, this sentence is
flawed in that the parenthetical phrase “if not impossible” is set off in
front but not behind: “The survey found increasing demand for customer
experiences that are difficult, if not impossible, to deliver with legacy
systems.”

4. Extraneous punctuation

Knowing which sensitive data need to be highly protected, where this
information sits within the organization, and what security mechanisms
need to be applied, are all key considerations for a sound information
security risk assessment.

A comma should not precede a verb unless it is the second of two commas
bracketing a parenthetical phrase: “Knowing which sensitive data need to be
highly protected, where this information sits within the organization, and
what security mechanisms need to be applied are all key considerations for
a sound information security risk assessment.”

Consumers have the right to speak out or complain, and to seek
compensation—payment or a replacement item—or redress—have a wrong
corrected.

Excessive punctuation often occurs when a sentence is cluttered with
commas, and a sentence should be recast or divided into two or more
sentences if more than a few commas appear (and semicolons are not included
to assist in sentence organization). When dashes are used to set off
parenthetical phrases, no more than one pair should be used, because
readers may have difficulty at first recognizing which parts of the
sentence are being bracketed.

Either revise the sentence so that only one
pair of dashes is needed, or replace dashes with parentheses, which because
the open and close parentheses are shaped differently, clearly indicate
what is contained within them: “Consumers have the right to speak out or
complain and to seek compensation (payment or a replacement item) or
redress (have a wrong corrected).” (Note, too, that the sole comma is
superfluous.)

6. Inconsistent Punctuation

Last year a man agreed to give up his drone system and promise not to
fly a drone for three years. . . . Last month, the FAA announced there
are now more registered drone operators in the United States than there
are registered manned aircraft.

If an optional punctuation mark is used in one sentence in a piece of
content, it should be used in any similarly constructed sentence.

Consider
the consistent inclusion of a comma after the short introductory phrase in
both sentences: “Last year, a man agreed to give up his drone system and
promise not to fly a drone for three years. . . . Last month, the FAA
announced there are now more registered drone operators in the United
States than there are registered manned aircraft.” (Note that “last year”
and “last month” serve the same adverbial function as specifically
in the second example, but such brief introductory phrases do not require
punctuation, though for consistency it is recommended.)

7. Incorrect punctuation

One person had to be airlifted off the site after the structure
collapsed Monday night, the rest were treated at an on-site medical
facility.

Because this sentence consists of two independent clauses, they must be
separated by a semicolon rather than a mere comma: “One person had to be
airlifted off the site after the structure collapsed Monday night; the rest
were treated at an on-site medical facility.” (A period is also
appropriate, but the close relationship of the two clauses allows for a
semicolon.)